Field
This disclosure relates generally to pressure sensors and more specifically to a pressure sensor device and method for testing the pressure sensor device.
Related Art
Micro-electro-mechanical systems (MEMS) is a technology used to make very small mechanical devices using integrated circuit processing technology. To indicate a relatively accurate pressure, pressure sensors first need to be calibrated using a known reference. Pressure sensors can be damaged during use in the field causing them to malfunction. Even if the pressure sensor is not damaged, it can lose calibration. Loss of calibration may result in erroneous pressure indications and cause overall system failure. Self-diagnostic testing can be used to detect if a sensor malfunctions or loses its calibration. Generally, a self-diagnostic test relies on two sense cells that are perfectly matched to each other. However, it is difficult to match sense cells due to, for example, process variation on the MEMS sensor, wire bond parasitic capacitances, etc. that may reduce accuracy of the test.
Therefore, a need exists for a method to test a MEMS pressure sensor that solves the above problems.